Electrophysiological device for the isthmus

Abstract

An intravascular electrophysiology (EP) device for the mapping and/or formation of lesions along the isthmus region of a heart that has particular utility in the treatment of atrial flutter. The EP device of the invention has an elongated shaft with a proximal section, a compound-curved or modified pigtail-shaped distal section, and a plurality of at least partially exposed electrodes disposed on an outer surface of the distal section. The electrodes are spaced along a length of the distal section and may be interspersed with at least one temperature sensor located between electrodes. The shape of the distal end of the device enables manipulation of the device by inserting its distal end in the tricuspid valve and retracting the device to bias the section having electrodes along the isthmus to achieve acceptable contact with the region so high frequency (e.g., RF) electrical energy delivered to the electrodes on the distal section of the EP device will form a lesion. Sections of the isthmus where treatment is desired but not reached by the section of the device biased against tissue by retraction may be ablated by repeating the steps of hooking the tricuspid valve at a different end location of the device and retracting to bias the electrodes against different tissue, simply advancing the section with electrodes to the desired site or retracting the device so a tip connected to an RF source will drop into a desired site where ablation may occur.

What is claimed is:  
     
       1. An electrophysiology device for ablating the isthmus region of the heart adjacent to the tricuspid valve, the device comprising: 
       an elongate shaft having a predetermined operable configuration including a proximal portion extending in an axial direction and an operable distal portion extending transverse to the axial direction;  
       a hook end region of the shaft distal portion generally extending toward or along the axial direction of the proximal portion of the elongate shaft in spaced relation thereto for anchoring to the tricuspid valve of the heart;  
       an interface region of the shaft distal portion extending between the proximal portion and the hook end region; and  
       a reverse curved portion of the interface region that bows the distal portion back inwardly for providing intimate contact with the isthmus region with retraction of the shaft distal portion and engagement of the hook end region with the tricuspid valve for an ablation operation on the isthmus region wherein the operable distal portion includes an arcuate region between the proximal region and the interface region with both the arcuate region and hook end region bowing outwardly opposite to the inward bowing of the interface region.  
     
     
       2. The device of  claim 1  wherein the shaft comprises a forming member of flexible, shape retentive material having a preformed configuration substantially matching that of the predetermined operable configuration of the shaft, and a sheath for receiving the forming member in an insertion configuration for delivery to the isthmus region restrained against returning to the preformed configuration thereof. 
     
     
       3. The device of  claim 1  wherein the operable distal portion including the hook end and interface regions define a compound curve. 
     
     
       4. The device of  claim 1  wherein the operable distal portion includes an arcuate region between the proximal portion and the interface region with both the arcuate region and hook end region bowing outwardly opposite to the inward bowing of the interface region. 
     
     
       5. The device of  claim 1  wherein the interface region includes an innermost portion thereof due to the inward bowing thereof and the hook region has a free end and an arcuate configuration bowing outwardly so that the free end is an innermost portion thereof. 
     
     
       6. The device of  claim 1  wherein the hook region has a distal end portion, and the reverse curved portion and distal end portions define respective tangent lines therewith such that the reverse curved portion tangent and the proximal portion of the shaft form an approximate angle of between 30 and 90 degrees, and the tangent lines form an approximate angle of between 60 and 90 degrees. 
     
     
       7. The device of  claim 1  wherein the hook region has a curved configuration generally opposite to that of the reverse curved portion with the curved hook region generally opening toward the shaft proximal portion. 
     
     
       8. The device of  claim 1  wherein reverse curved portion is bowed inwardly in a direction generally toward or along the shaft proximal portion for biasing the reverse curved portion into engagement with the isthmus region of the heart.